N-monoformyl-n, n&#39;-disubstituted ethylenediamines



Patented Nov. 2, 1948 UNITED STATES} PATENT emee N-MONOFORMYL-N,N'-DISUBS TITUTED ETHYLENEDIAMINES i a I i Ferdinand B. Zienty, St. Louis, Mo., as i to Monsanto Chemical Company,.St a corporation of Delaware H v u No Drawing; Application une 1945, V 7 Serial No. 598,923

This invention relates to N,l l'-dialkyl, N,N'-diaralkyl, ,N,N'-diaryl and N,N'-dicycloalkyl ethylenediamines and more particularly to N-formyl derivatives thereof and to a novel process for preparing them.

' I have found "that N-monoformyl derivatives of N,N'-dialkyl, N,N'-diara1kyl, N,N'-diaryl and N,N'-dicycloalkyl ethylenediamines may be prepared in good yield under certain circumstances. Acylated derivatives of ethylenediamines have been prepared by reacting certain acyl chlorides such as acetyl chloride or benzoyl chloride with ethylenediamine. However, the yields of the N-monoacyl derivative are very poor. Attempts to react formic acid with ethylenediamine have failed to yield. any appreciable amount of an N- formyl ethylenediamine. I have found it necessary to react ethylenediamine with an alkyl formate such as ethyl formate, for example, by cautiously mixing 0.3 mole of ethyl formate with 12 moles of ethylenediamine and subsequently .fractionally distilling the reaction mixture under reduced pressure and recovering the fraction boilring at approximately 90-110/14 mm. The yield of N-formyl ethylenediamine by this process was relatively low. I 1 i According to the present invention, generallystated; N-monoformylderivatives of N,N-dialkyl, N,N-diaralkyl, N,N-diaryl and N,N'-dicycloalkyl ethylenediamines may be prepared in good yields byheating formic acid and an N,N'-di-substituted ethylenediamine of the type described under conditions such that the reactants are dehydrated to the-extent that substantially only one mole of Water. .is ,split off from the reactants for each mole of the N,N'-di-substituted ethylenediamine starting material. To. accomplish this, the reaction is conducted in the presence of the water of dehydration thus-evolved. This in turn is accomplished most readily by heating the reaction mixture to the. appropriate dehydration temperature under a reflux condenser, whereby the water of dehydration which tends to vaporize at the reaction temperature is returned to the reaction mixture. It istobe understood that the appropriate temperature of dehydration will vary with the specific properties of the N,N'-di-substituted ethylenediamine starting material. In some instances,,- the reaction mixture may actually reflux at theltemperature of dehydration whereas in other instances the presence of the reflux condenser in the system merely insures that the water of dehydration will be retained in the reaction mixture. I l

ln'apreferred embodiment of my invention the 12 Claims. (01. rot -561$ 40 be better at: the lower ratio.

formic acid ma bete teeeu eteneelly to the reaction temperature and the N,N'-di-subs tituted ethylenediamine may be added gradually to the formic acid, the reaction held at the temperature of the desired monodehydration ofthe reactants and the system being enclosed and equipped with In a further embodiment ofmy invention, the

formic acid andthe N,N"-di-substituted ethylenediaminemay be mixedat a temperature below the dehydration point andsubsequently heated undera reflux condenser to split off substantially one mole of Water for the formation of the cor responding N monoformyl-N,N-di substituted ethylenediamine. The reaction temperature may vary with the particular respective reactants emplayed; Forexampla-in the preparation of N- monoformyl-N,N -dibutyl ethylenediamine, the

reaction temperature is desirably in the range of 102-113 C. In the preparation of N-monoformylthe reaction temperature may be elevated above the temperature for monodehydration of the product. I-Iowever, anextensive elevation of the 'temperature'of the reaction mixturetends to give rise to theformation-of di formyl derivatives Whichin this instance are undesired products. The ratio o'f formic acid to N,N'-di-substituted ethylenediamine may be'varied over a wide range, for example, from 3:1 to 10:1 oreven higher depending-upon the particular reactants selected.

;For example, in the preparation of N-monoformyl-N,N'-dibutyl ethylenediamine, theratio is desirably 3:1. In the preparation of N-monoformyl-N,N'-dicyclohex'yl ethylenediamine, the ratio is rdesirably 61.1 and may be as high as 1011. In general, the yi'eld. of-the desired product tends to The process of the present invention may be applied to the preparation of N-monoformyl derivatives of N,N'--clialkyl, N,N-diaralkyl, N,l\l'-diaryl aand"N,N'-dicycloalkyl ethylenediamines in which 'the' alkylradicals may have from 1 to 24 carbon atoms or more and may be branched or" straight chain structures, the aryl radicals may I be mondcyclic or polycyclic and the cycloalkyl radicals mayha've from 3 to 6 carbon atoms. The 0 hydrogen atoms of theethylene residue of the N,N'-di-subst ituted ethylene-diamines may be substitutedjby any desired radicals, for example alkylgcycloallrylqarylalkoxy; aryloxy, alkoxyalkyl or-aryloxyalkyl radicals. Itis desirable to employ. 5 N,N"-di-substituted ethylenediamines which coni tain no acyl-reactive groups other than the hydrogen atoms of the two amino radicals of the ethylenediamine, since it is not always, though sometimes, possible to insure that the formyl radical will appear on one of the two amino radicals of the diamine. .The following .compounds .are typical products of the process of the present invention:

The N-mnof0rmy1. derivatives of the ethylenediamines are useful as. intermediates in the preparation ot plasticizers for cellulose esters and syn thetic resin; plastics, in the preparation of insecticidal and fungicidal toxicants and int-he preparationsof decorative ingredients for plastic .compositions. :The N-mono-iormyl derivatives of the ethylenediamines range .in form from liquids to waxyesolids and are surprisingly stable, even at elevatedtemperatures, for example in' therange of--200- 230-C.

The following exampleswill serve to illustrate thenovel process and products "of the present invention. These examples .are to be :construed merely as illustrative and notes limiting the invention except as defined in the appended-claims.

Example I Technicalformic acid 1-08- grams. or 2 moles) was heated under a reflux condenserwithzstirring in-an oil-bath havingwa temperature of 130- C., and .ll2...grams (0.5 mole) of.:N,N-'--dicyclohexyl ethylenediamine was added slowlyduring the courseof three hours. -Atthis point the reactionwas substantially. complete and the resulting mixture-'was-t-hen cooled to 30-C.,;poured-' into 500 cc. orwaterand the resulting mixture was filtered tov remove solid material. The.fi1trate was renderednalkaline by theuadditionof excess 50%=- sodiumhydroxide solution and? the oily product was.

separated and disti-lledinvacuo. .Yield, 85% of N iormyl N,N'-dicycl-ohexyleethylenediamine; boiling point,- 200-205 C./8 mm.

Example" II A mixture of I mole of 'N,N'-dibenzy1-ethy1enediamine and 5 moles of technical formic'acid'iwas prepared at a temperaturegof-7'5iC. :The reaction mixture was heated under a refiuxzcondenser with agitation ina-n oilbath, the temperatureof which was slowly raised to apoint-"Withihi therangef-of 125-135 Cnand maintainedwithin thatrange for thirty. minutes. The reactionmixturewasithereaftercooled by addition of-cold. waterand filtered to remove solids. line and. N-formyl-N-N d-ibenzyl ethylenediamine was recovered from theresulting mixture.

Example III A mixture. of 108. grams (2 moles -of.85%-formic acid and 106 grams.(0.5 m01e)-.ofwN,N-dipheny1 ethylenediamine was. heated with stirring r-inea The'filtrate was renderedalka- 4 in a bath held at 130-135 C. The reaction temperature was 108 C. throughout the reaction period of 3.5 hours. The mixture was cooled to 90 C. and poured into 500 cc. of water. A red, viscous liquid formed a separate layer over the reactionmix-ture. .lThis liquid .wasldecanted, filteredan'd rendered alkaline "with an excess of sodium hydroxide solution.

This product Weig-ht; 19 grams. The product was recrystallized frolnmethanol. Melting point, 65-66 C.

Example IV Two moles of technical formic acid and 0.5 mole or 1 N,N =dibutyl ethylenediamine were mixed at roomtemperature C.) and the mixture was placedrimaflask equipped with a thermometer, a.

stirrer and a reflux condenser and heated for 3 hours-by means ofanoil bath held at. a temperature of..'1-30 During this time the reaction temperature rose'from 102 C. to'113 C. "The mixture was heated for one hour longer arid was then cooled't0"50 'C. and poured into water. "Ah.

excess .of 50% caustic soda solution wasaldded. Benzene was. added to dissolve the water insolublepro'duct and the'benzene solution waslse'pae. rated .from the Water layer and distilled. 'lTh'e fraction boiling at'153-'-155 0.77 mm; Wasr ebbV-' ered. This fraction was N-form'ylNQN d ibutyl ethylenediamine. Yie1d,'4'7grams.

' -Ea'amp'Ze V One mole of "N,N' diethyl ethylenediaminewas slowly added over a period of threeh'ours"t'o 3 moles -of technical formic acid heated under arefluxcondenser'with agitation inan oil loath mam tained at a temperature of C. The'reaction j mixture was thereafter" cooled by the'addi'tion of cold water and the resulting'solution' wa-s filtered. The filtrate was rendered alkaline"and-N formyl- N.N' idithyl ethylenediamine 'wasrecover'edfrom the'resultingmixture.

Example-VI One mole of N,N'-dipropyl ethylenediamine arid 'ii moles of technical-iormic acid were mixed at "room temperature (25 C.) 'and heated under a reflux coridenser with agitation by means er am oil 'hath' maintained at-sa temperature er -13. After the reaction was complete, the rreaction temperature was cooled by the addition-"of "-c'o'id water and "the resulting "product was filtered.

The filtrate was rendered alkaline and N iormyl- N,-N dipropy1 ethylenediamine was zrecovere'd' from the resulting mixture.

Example VII .One :mole of N,'N"-idld0dCYl ethirlenedianflne was .heated with agitation in an oil bath; maim tain'ediat sa itemperaturer of. 7 520 and; 5 lmolestpi technical formic :acid 'rwerewadded thereto. male temperature :of the: oil: bath-was raisedf toi andmaintained: at that point 1:1rrtil the-'reactien wasrcomplete. .L Thei reaction mixture awas'im'aintainedmnderza' reflux condenser 'duringfthe heating'period. The"reaction lmixtureltwas thereafter cooledmby: pouring it'intotcoldiwater. vmnermmr tut-e wasfrender'e'd alkaline, andNformyl-NiN-h 'didodecyl etl'iylenediamine was "recovered from the'r'esulting mixture.

'ExampZe'VII I Six moles of technical formic acid was heated -'und.er.-arefiux condenser witlragttatiombysmems The solid product i E which separated from the solution was N-formyl- N,N' -diphenyl ethylenediamine. "was filtered o'ffl washed with water and dried.

of. an 1011' bath .maintained' at a temperature of 135-145" C. and 1 mole of N,N'-didodecyl-,1-tridecylciethylenediaminei was slowly .added over. a period oftwo hours. sAfterthereaction was complete the reactionmixture was cooled by pouring it into cold water and the mixturewas rendered alkaline. N-formyl N,N' -didodecyl-1-tridecyl ethylene diam-inc was recovered from the mixture.

Example IX One mole of N,N-dicyclohexyl-1-methyl-2- hep'tyl ethylene diamine was mixed with 5 moles of technical formioacidat room temperature C.) and the mixture was heatedunder a reflux condenser with agitation inan oil bath maintained at a temperature of 125-135? C. for two hours. The reaction mixture was poured into cold water. the resulting mixture wasfiltered and the filtrate was rendered alkaline. "N formyl- NN'-dicyc1ohexyl-l-methyl-Z-heptyl ethylenediamine was recovered from the mixture. 1

Example X l a One mole of N,N "-.dinaphthyl ethylenediamine was mixed with 5 moles of technical formic'acid at room temperature (25 C.) and the mixture was heated under a reflux condenser with agitation in an oil bath maintained at a temperature of 125- 135 C. for two hours. The reaction mixture was poured into cold water, the resulting mixtur was filtered and the filtrate was rendered alkaline. N-formyl-N,N dinaphthy1 ethylenediamine was recovered from the mixture.

1 1 Example XI One mole of N,N'-dicy-clopropyl ethylenediamine was mixed with 5 moles of technical formic acid at room temperature (25 C.) and the mixture was heated under a reflux condenser with agitation in an oil bath maintained at a temperature of 125- 135 C. for two hours. The reaction mixture was poured into cold water, the resulting mixture was filtered and the filtrate was rendered alkaline; N-formyl N,N' dicyclopropyl ethylenediamine was recovered from the mixture.

Example XII A 0.5 mole portion of a technical mixture of monohydric aliphatic alcohols containing from 8 to 18 carbon atoms and known to the trade as "Lorol" alcohols was converted to the corresponding alkyl chlorides. Of the quantity of mixed alkyl chlorides thus obtained, a 0.1 mole portion, calculated on the basis of the average chlorine content of the mixture, was heated at approxim-ately 120 C. with 0.1 mole of ethylenediamine'. The resulting mixture of N,N'.-dialky1 ethylenediamines recovered from the reaction mixture contained alkyl radicals having from 8 to 18 carbon atoms. This material was then heated under a reflux condenser with 0.4 mole of 85% formic acid at a temperature of 100-130 C. until substantially one mole of water had split off for each mole of the N,N-dialky1 ethylenediamine mixture, calculated on the average molecular weight of the mixture. The resulting N-formyldiamines,

preparation" of insecticidal, nliticidal and -fun icidal compositions.

Ificlainia 1. A method of preparing an N-monofcrmyl as rivative of an N,N'-.di-substituted. ethylenediamine comprising heating in a reaction: zone formic acidand an ethylenediamine selected from the group consisting of N,N'-dialky1 ethylene-1 N,N dlaralkyl ethylenediamines, N,N'-diaryl ethylenediamines and 1N.;N'-.dicycloalkyl ethylenediamines at a temperature at which substantially one mole of water splits off from. the reactants for each mole of said ethylenediamine, retaining said water in said reaction zone during the course of the reaction and subsequently recovering. said N-formyl derivative from the reaction mixture. i 1 u 1 .2. A method of preparing an N-monoformylderivative of an N,N'-di-substituted ethylenediamine comprising heating in a reaction zone i formic acid and an ethylenediamine selectedfrom. the group consisting of N,N-dia1kyl ethylene diamines, N,N'-diara1ky1 ethylenediamines, N,N'- d-iaryl ethylenediamines and N,N'-.di-cycloalky1 ethylenediamines at atemperature in the rangeiofi 100130 C. until substantially one mole of water is split off from the reactants for each mole of said ethylenediamine, retaining said water in said action zone during the course of thereaction and subsequently recovering said N-formylderivative from the reaction mixture. l

3. The process as defined in claim? 1' in which the ratio of formic acid-to NNT-di-substituted ethylenediamine is in' the rangepf 3:11 10: 1.

4. A method of preparing an N-monoformyl derivative of a'n N,N' -di-substituted ethylenediamine comprising heating formic acid in a reaction zone under reflux conditions at a temperature intherange of IOU-130 0., adding thereto an'ethylenediamine selected from thetgroup consisting of N,N-dialky1 ethylenediamines, N,N'-

. diaralkyl ethylenediamines, N,N'-diaryl ethylenediamines and N,N'-dicycloalky1 ethylenediamines until the ratio of formic acid to said ethylenediamine is in the range of 3:1 to 10:1, maintaining the temperature until substantially one mole of water is split ofi from the reactants for each mole of said ethylenediamine, retaining said water in said reaction zone during the course of the reaction and subsequently recovering said N-formyl derivative from the reaction mixture.

5. A method of preparing N-monoi'ormyl-N,N-

i dibutyl ethylenediamine comprisingiheating in a reaction zone formic acid and N,N-dibutyl ethylenediamine at a temperature in the range of 100- 130 C. until substantially one mole of water splits oiT from the reactants for each mole of said N,N- dibutyl ethylenediamine, retaining said water in said reaction zone during the course of the reaction and subsequently recovering N-monoformyl- N.N'-dibutyl ethylenediamine from the reaction mixture.

N,N-d-ialkyl ethylenediamine mixture contained alkyl radicals having from 8 to 18 carbon atoms. The N -formyl derivatives were recovered from the reaction mixture by quenching the reaction mixture with water, filtering, alkalizing the filtrate, extracting the filtrate with benzene and recovering the mixture of N-formyl-N,N'-dialky1 ethylenediam-ines from the benzene extract. This mixture was found to 'be particularly useful in the 

